Railroad freight car draft gear friction modifying insert

Abstract

A railroad freight car draft gear includes a friction clutch assembly with friction members arranged in operable combination with an actuator. Each friction member has an outer friction surface which slides along a mating friction surface. A spring assembly is provided for absorbing, dissipating, and returning energy imparted to the draft gear. Recesses are provided on the respective mating friction surfaces of the draft gear. A uniquely designed preformed friction modifying insert is pressed into each recess on the clutch assembly components. Each insert includes an elongated leg having projections extending radially outward from opposed surfaces on the insert leg. Each friction modifying insert is furthermore configured to include a convex inner contact surface to facilitate insertion and active contact along with flared inner edges to improve fit between the insert and related draft gear components.

What is claimed is: 
     
         1 . A railroad freight car draft gear, comprising:
 a friction clutch assembly including friction members arranged in operable combination with an actuator adapted for longitudinal reciprocation during operation of said draft gear, and with each friction member having an outer friction surface which slides along a respective mating surface;   a spring assembly for absorbing, dissipating, and returning energy imparted to said draft gear;   with recesses being provided on the respective mating surfaces on the draft gear; and   with a preformed friction modifying insert being pressed into each recess, with each insert including an elongated leg having opposed ends and projections extending radially outward from the leg and disposed between said ends, and wherein the projections on each insert includes a plurality of adjacent and raised ribs extending radially outward from the leg of each insert, and with each insert serving to facilitate reciprocatory movements of said friction clutch assembly relative to mating components during operation of said railroad freight car draft gear.   
     
     
         2 . The railroad freight car draft gear according to  claim 1 , wherein each insert is formed from one of the following materials: brass alloy, bronze alloy, lead alloy, impregnated plastics. 
     
     
         3 . The railroad freight car draft gear according to  claim 1 , wherein the leg of each insert has first, and second generally parallel surfaces joined by an outer end and a convex inner end. 
     
     
         4 . The railroad freight car draft gear according to  claim 1 , wherein any two longitudinally adjacent projections on each insert radially extend from opposed generally parallel surfaces on each insert and are offset relative to each other. 
     
     
         5 . The railroad freight car draft gear according to  claim 1 , wherein each, insert includes a second elongated leg having opposed ends and at least one projection extending radially outward from the second leg and disposed between said ends thereof. 
     
     
         6 . The railroad freight car draft gear according to  claim 5 , wherein the elongated legs on each insert are interconnected to each other. 
     
     
         7 . A railroad freight car draft gear, comprising:
 an elongated metal and hollow housing;   a friction clutch assembly arranged in operable combination with said housing, said friction clutch assembly including friction members arranged in operable combination with an actuator adapted for longitudinal reciprocation during operation of said draft gear, and with each friction member having an outer friction surface which slides along a mating friction surface;   a spring assembly for absorbing, dissipating and returning energy imparted to said draft gear;   with recesses being provided on the mating surfaces on the draft gear;   with a preformed friction modifying insert being pressed into each recess for facilitating reciprocatory movements of said friction clutch assembly during operation of said railroad freight car draft gear, with each preformed insert including an elongated leg having opposed ends defining a length of said insert, and wherein each insert has and an outer end extending substantially the length thereof and which is disposed adjacent the closed end of the respective recess after the insert is pressed thereinto, and a flared inner end extending substantially the length of the insert and which is disposed toward the open end of each recess to enhance the fit of each insert when mating tolerances of the insert and the respective recess into which the insert is pressed approach minimum.   
     
     
         8 . The railroad freight car draft gear according to  claim 7 , wherein each insert is formed from one of the following materials: brass alloy, bronze alloy, lead alloy, impregnated plastics. 
     
     
         9 . The railroad freight car draft gear according to  claim 7 , wherein the leg of said insert has first, and second generally parallel surfaces joined by an outer end and a convex inner end. 
     
     
         10 . The railroad freight car draft gear according to  claim 7 , wherein each insert includes a plurality of longitudinally adjacent and raised projections extending radially outward from the leg of the insert and offset relative to each other. 
     
     
         11 . The railroad freight car draft gear according to  claim 10 , wherein any two longitudinally adjacent projections on each insert radially extend from opposed generally parallel surfaces on said insert. 
     
     
         12 . The railroad freight car draft gear according to  claim 11 , wherein each projection includes a raised rib, with each rib extending only partially about the leg of the insert. 
     
     
         13 . The railroad freight car draft gear according to  claim 7 , wherein each insert includes a second elongated leg having opposed ends, with the second leg of said insert having at least one projection extending radially outward therefrom and disposed between said ends thereof. 
     
     
         14 . The railroad freight car draft gear according to  claim 13 , wherein the elongated legs on each insert are interconnected to each other. 
     
     
         15 . A railroad freight car draft gear, comprising:
 an elongated housing having external walls extending between a closed end and an open end, with the open end of said housing defining a friction bore having a curved internal surface;   a friction clutch assembly arranged within the open end of said housing, said friction clutch assembly including at least two friction shoes arranged in operable combination with an actuator adapted for longitudinal reciprocation within the friction bore of said housing during operation of said draft gear, and with each shoe having an angled outer surface which slides along the internal surface of said friction bore;   a spring assembly disposed within said housing between the closed end of said housing and said friction clutch assembly for absorbing, dissipating, and returning energy imparted to said draft gear;   with recesses being cast into the internal surface of the friction bore defined by said housing, with said housing defining a closed inner end and an open outer end for each recess; and   with a preformed friction modifying insert being pressed into each recess of the friction bore defined by said housing ends for facilitating reciprocatory movements of said friction clutch assembly during operation of said railroad freight car draft gear, with each insert being configured with an elongated and curved leg having opposed ends defining a length of said insert, with the curvature of said insert leg generally corresponding to the curvature of the internal surface of said friction bore, and wherein an outer end of said insert extends the length thereof and is disposed adjacent the closed end of the respective recess after said insert is pressed thereinto, and with an inner end extending the length of said insert and having a convex profile which initially projects past the curved internal surface of said friction bore after said insert is pressed thereinto.   
     
     
         16 . The railroad freight car draft gear according to  claim 15 , wherein each insert is formed from one of the following materials: brass alloy, bronze alloy, lead alloy, impregnated plastics. 
     
     
         17 . The railroad freight car draft gear according to  claim 15 , wherein the leg of said insert has first, and second generally parallel surfaces joined by an outer end. 
     
     
         18 . The railroad freight car draft gear according to  claim 15 , wherein each insert includes a plurality of longitudinally spaced and raised projections extending radially outward from the leg of the insert. 
     
     
         19 . The railroad freight car draft gear according to  claim 18 , wherein any two longitudinally adjacent projections on each insert radially extend from opposed generally parallel surfaces on said insert and are offset relative to each other. 
     
     
         20 . The railroad freight car draft gear according to  claim 18 , wherein each projection is configured as a raised rib, with each raised rib extending only partially about each leg of the insert. 
     
     
         21 . The railroad freight car draft gear according to  claim 15 , wherein each insert includes a second elongated leg having opposed ends and at least one projection extending radially outward from the second leg and disposed between said ends thereof. 
     
     
         22 . The railroad freight car draft gear according to  claim 21 , wherein the elongated legs on each insert are interconnected to each other. 
     
     
         23 . A railroad draft gear friction modifying insert for facilitating reciprocatory movements of a friction clutch assembly during operation of a railroad freight car draft gear, with said insert having an elongated leg with opposed ends defining a length of said insert therebetween, and wherein an inner flared end of said insert extends substantially the length of said insert and is disposed adjacent an open end of a respective recess defined by a mating surface on said draft gear after said insert is pressed thereinto, and with the inner end of said insert having a convex profile. 
     
     
         24 . The railroad freight car friction modifies insert according to  claim 23 , wherein said insert is formed from one of the following materials: brass alloy, bronze alloy, lead alloy, impregnated plastics. 
     
     
         25 . The railroad freight car friction modifying insert according to  claim 23 , wherein the leg of said insert has first and second generally parallel surfaces joined by an outer end. 
     
     
         26 . The railroad freight car friction modifying insert according to  claim 23 , wherein said insert includes a plurality of longitudinally adjacent and raised projections extending radially outward from the leg of the insert. 
     
     
         27 . The railroad freight car draft gear according to  claim 26 , wherein any two adjacent projections on said insert extend from opposed generally parallel surfaces on said insert. 
     
     
         28 . The railroad freight car draft gear according to  claim 26 , wherein each projection includes a raised rib, and wherein each raised rib extends only partially about the leg of the insert. 
     
     
         29 . The railroad freight car draft gear according to  claim 23 , wherein said insert includes a second elongated leg having opposed ends and projections extending radially outward from the second leg and disposed between said ends thereof. 
     
     
         30 . The railroad freight car draft gear according to  claim 29 , wherein the elongated legs on said insert are interconnected to each other.